KPH to MPH

02/01/2022

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Converting MKIII Supra Digital Dash Legends from KPH to MPH

This mod changes the KPH legends to MPH on the digital dash. I personally did not come up with this mod so, claim no credit however, due to the original web site no longer being available I have posted information here to allow people to continue to carry out this mod.

This mod only swaps the legends to MPH, it does not altar the speedo reading to MPH. For this you will need to fit an electronic KPH to MPH convertor to the speedo signal.

On the 2.5TT 1JZ-GTE cars this speedo convertor needs to be a very specific module, a standard type will not work properly like on other Supra models .

Firstly you will need to remove the digital instrument cluster and disassemble it carefully by, basically removing all the screws you can see on the the assembly. Note where they come from as there are a number of different screws which go in specific places.

You will need to remove the water temperature display to allow you to then remove the main speed display unit, it unplugs from the speedo display PCB.

Once out, you need to open up the speed display by removing the 7 x 7mm studs holding the boards together.

With a pair of good precision cutters, locate and cut the following pins on the bottom of the main speed VFD unit.

Cut Pin 21 - located above C1

Cut pin 51 - Located above C24

Cutting these pins knocks out the KPH legends on the VFD.

Now turn the VFD over as you will need to make 2 links on the back of the PCB for which you’ll need a soldering iron and some thin hook up cable.

These links put power onto the MPH and MILES legends.

Link display pin 51 to pin 53 - Pin no’s marked at end of each run on PCB, just count in between the numbers.

Link display pin 21 at bottom of board to display pin 138 at top of board.

Now, clean the screens up while they are out, re light the scales if the bulbs have blown and reassemble the cluster.

You may want to test it before you screw it all together just to make sure otherwise, just pop it all back together and reinstall with MPH and MILES instead of KPH :)

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